Recording vocals can be challenging, and one of the most common problems encountered is sibilance. Sibilance refers to the hissing or harsh sounds that occur when the singer pronounces words with ‘s’, ‘sh’, ‘ch’, ‘t’, and ‘z’. These sounds can be distracting and may make the vocals sound unpleasant, especially when mixed with other instruments.
To address this issue, audio engineers often use a de-esser, a tool that helps to reduce sibilance in vocals. In this article, we will discuss what a de-esser is, how it works, and how to use it when recording vocals.
What is a de-esser?
A de-esser is a tool that is used to reduce or remove sibilance from a vocal recording. It works by detecting the frequencies where sibilance occurs and then reducing their levels. De-essers are commonly used in mixing and mastering, but they can also be used during recording to prevent sibilance from being recorded in the first place.
De-essers come in different forms, including hardware and software. Hardware de-essers are physical devices that are connected to the audio chain, while software de-essers are plugins that are inserted into a digital audio workstation (DAW) or used as standalone applications.
How does a de-esser work?
A de-esser works by detecting and reducing the frequencies that cause sibilance in a vocal recording. When a singer pronounces words with ‘s’, ‘sh’, ‘ch’, ‘t’, and ‘z’, the sound waves produce high-frequency content that can be harsh and unpleasant to listen to.
A de-esser typically uses a bandpass filter to isolate the frequencies where sibilance occurs. The bandpass filter is designed to allow only a narrow range of frequencies to pass through, which makes it easier to target the sibilant sounds. Once the sibilant frequencies are isolated, the de-esser reduces their levels using either gain reduction or frequency-dependent compression.
Gain reduction is a technique that reduces the level of the entire audio signal when the sibilance frequency is detected. This technique can be effective, but it can also affect the overall tone and volume of the vocal recording.
Frequency-dependent compression is a more advanced technique that only reduces the level of the sibilant frequencies, leaving the rest of the signal untouched. This technique allows for more precise control over the reduction of sibilance and can produce better results than gain reduction.
How to use a de-esser when recording vocals
When using a de-esser during recording, the goal is to prevent sibilance from being recorded in the first place. Here are the steps to follow when using a de-esser during recording:
- Set up the de-esser: Connect the de-esser to the audio chain and set it up according to the manufacturer’s instructions. If using a software de-esser, insert it as a plugin in the DAW.
- Test the signal: Have the singer perform a few lines of the song while monitoring the signal. Look for any sibilance or harshness in the vocals.
- Adjust the de-esser settings: Adjust the de-esser settings to reduce the sibilance. Start by setting the threshold, which determines the level at which the de-esser begins to reduce the sibilant frequencies. Set the threshold low enough to catch the sibilance, but not so low that it affects the overall sound of the vocals. Next, adjust the ratio, which determines the amount of reduction applied to the sibilant frequencies. Set the ratio to a level that reduces the sibilance but doesn’t affect the overall tone of the vocals.
- Test again: Have the singer perform another few lines of the song while monitoring the signal with the de-esser engaged. Listen for any changes in the overall sound of the vocals and make any necessary adjustments to the de-esser settings.
- Record the vocals: Once you are satisfied with the de-esser settings, record the vocals. Monitor the signal to ensure that the de-esser is working correctly and that sibilance is being reduced.
- Review the recording: After recording the vocals, review the recording to ensure that the sibilance has been adequately reduced. If necessary, make any additional adjustments to the de-esser settings and re-record the vocals.
Tips for using a de-esser during recording
Here are some tips for using a de-esser during recording:
- Use a high-quality de-esser: Invest in a high-quality de-esser to ensure that you get the best possible results.
- Set the de-esser correctly: Take the time to set the de-esser correctly. Adjust the threshold and ratio settings to ensure that the de-esser is reducing the sibilance effectively without affecting the overall sound of the vocals.
- Monitor the signal: Monitor the signal during recording to ensure that the de-esser is working correctly and that sibilance is being reduced.
- Communicate with the singer: Let the singer know that you are using a de-esser and explain how it works. This will help the singer understand why the vocals may sound slightly different than what they are used to.
- Use a pop filter: A pop filter is a device that is placed in front of the microphone to reduce plosives and sibilance. Use a pop filter in conjunction with a de-esser to further reduce sibilance.
Using a de-esser when recording vocals can be an effective way to reduce sibilance and improve the overall sound of the vocals. De-essers work by isolating and reducing the frequencies where sibilance occurs. When using a de-esser during recording, it is important to set it up correctly, monitor the signal, and communicate with the singer. By following these tips, you can achieve professional-quality vocal recordings with minimal sibilance.